<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style lang="">
    * {
      padding: 0;
      margin: 0;

    }
    .container {

      display: grid;
      grid-template-columns: repeat(3, 10px);
      grid-template-rows: repeat(3, 10px);
      grid-template-areas:  'header header .'
                            'main main sider'
                            'footer footer .';
      row-gap: 5px;
      column-gap: 8px;

    }
    .container > div {
      border: 1px solid black;
    }
  </style>
</head>
<body>
  <div class="container">
    <div></div>
    <div></div>
    <div></div>
    <div></div>
    <div></div>
    <div></div>
    <div></div>
    <div></div>
    <div></div>
    <div></div>
  </div>
</body>
</html>